Abstract

Copperoxidation,ionization, and penetration into a low-polymer, SiLK-D™, are studied here. It is demonstrated by exposure to an oxidizing plasma and subsequent bias-temperature-stress experiments that an increase in the content of reactive or weakly bound oxygen at the SiLK-D™ surface in contact with the copper leads to the oxidation of the copper and injection of the copper into the polymer. The oxidation and injection are driven by the applied external electric field. X-ray photoelectron spectroscopy has been used to characterize the surface oxygen content on as-deposited (low oxygen content, the reference) and oxygen plasmatreated films (high surface oxygen content). Capacitors were fabricated on both materials and bias temperature stress tests were done for several plasma exposure times and for external electric fields of 1, 0.5, and to detect copperionization and injection. With an electric field of only , copper injection was not detectable even though oxygen at the SiLK-D™ surface had been increased by exposure to oxygen plasma.

Received 01 February 2006Accepted 10 April 2006Published online 12 May 2006

Acknowledgments:

The authors acknowledge Semiconductor Research Corporation and Texas Instruments for supporting this work. The authors thank Dr. Carol Mohler at Dow Chemicals for supplying the SiLK-D™ films used in this study. Rob Planty performed the XPS scans presented in this work.